Charles e



(No Model.)

O.B.DRE SSLER. DYNAMO ELECTRIC MACHINE.

No. 498,537. Patented May 30, 1893.

fig-:2.

UNITED STATES PATENT OFFICE.

CHARLES E. DRESSLER, OF NEW YORK, N. Y.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 498,537, dated May 30, 1893.

Application filed October 6, 1891- Serial No. 407,829- (No model.)

To aZZ whmn it may concern.-

Be it known that 1, CHARLES E. DRESSLER, of the city of New York, in the county and State of New York, have invented certain new and usefulImprovements in Dynamo-Electric Machines and Motors, which invention is fully set forth and illustrated in the following specification and accompanying drawings.

The object of this invention is sufficiently indicated by its title.

The invention will first be described in detail and then particularly set forth in the claims.

In theaccompanyingdrawings Figure1,isa longitudinalsectionalelevation of the machine showing it connected so that it may be used either as a dynamo or as a motor. Fig. 2 is an end view of Fig. 1, looking to the right, the part to the left of Fig. 2 being shown out of line with the center of said figure for the purpose of clearer illustration. Fig. 3 is an enlarged view, detached, of one of the field-magnets shown in the preceding figures. Fig. 4 shows a modified detail of parts and connections, hereinafter described.

In said figures the several parts are indicated by reference numbers and letters as below described.

The number 1 indicates the base of the machine which may be made of any suitable material, preferably cast-iron. Mounted upon said base and secured thereto in any suitable manner are two short cylinders or rings 2, preferably of wrought iron. Upon the inner periphery of said rings, bolted or otherwise secured theretoare field magnets 3, also of wrought iron. These magnets are of spool form as shown in Figs. 1, 2 and 3. The spools are preferably elongated instead of circular and are suitably wound with insulated wire 4, in any well known manner, in order to make them electromagnets when a current of electricity is passed through said wire. Said magnets are preferably bored out, as shown in Fig. 3, and, in the holes bored, hardened steel pins 5 are inserted, which pins after being electrically excited will retain residual magnetism and thus make the electrofield-magnets in part permanent magnets also. By thus constructing the field-magnets, the machine will soon reach its maximum generative power without energizing the field from any external electrical source.

The field-magnets being thus complete, the armature is constructed as follows: Upon a suitable shaft 6, preferably of steel, mounted in suitable end bearings (not shown) is secured a sleeve or annular core 7, of soft iron. Said core is divided into a central section and two end-sections at the points 8, which sections or portions are suitably secured together across the cuts or spaces 8, by non-magnetic fastenings so that all three sections of the core may revolve together. A convenient method of securing said sections together, is to radially insert brass screws tapped half into one section and half into the other at the points or cuts 8, as shown by the dotted lines 9. The core 7 however may be made continuous or unbroken, but by dividing it the tendency to generate eddy-currents between the induction coil and armature is lessened or prevented. The end-sections of the core 7 may be suitably secured to the shaft 6, so as to revolve with it, through or by means of the short sleeves 10, of non-magnetic metallic material. The end-portions of said core 7 being thus securely fastened to the shaft 6, so as to rotate with said shaft, the middle portion of said core 7 will also rotate with said shaft by the convenient insertion of the brass screws above mentioned or by any other means that may be employed for the same purposeif it be desired to have said portion rotate with said shaft. But it is immaterial whether said middle portion rotates or remains stationary. It may be supported in place in any suitable manner-a certain insulation such as the spaces 8, or other insulation, being preserved between said middle and end-portions. The non-magnetic screws mentioned, or equivalent nonmagnetic means, if used,need not be of brass, but should be of some non-magnetic material. The quality of electric conductivity, however, of such fastenings, while not desirable as such does not militate against their use, as none of them is in an electric circuit, each fastening being in contact only with the separated surfaces of two magnets. The construction above described diminishes the tendency of the counter-electro-1notive force 2 of the field.

' tate with the armature.

inductively generated in the coil 14, from reacting, so to speak, upon the armature polepieces, for as said coil tends to impart magnetism of opposite direction in the middle portion of core '7, such current, but for the insulating spaces 8, would in turn react upon the magnetism generated in the armature pole-pieces and, by opposing such magnetism, tend to diminish its force. Upon said endsectlons of the core 7, are mounted and secured thereto the armature magnets or pole pieces 11, of the form shown in the drawings preferably elongated spools like the field-magnets, but also preferably laminated, or built up into shape of soft plate-iron, instead of being madesolid. Thesearmature-pole-pieces 11, are wound with insulated wire 12, in a suitable and well known manner.

In order that the armature magnets or polepieces may be placed in position within the fieldpole-pieces or magnets, one end armature-magnet is made so that it may be slipped into position and secured after the other endmagnet has been put in place. This is done to allow of the insertion, between the endpole-pieces of both the armature and field, of the fixed spool 13, now to be described.

The spool 13, of non-magnetic material, is circular and may be secured to either the base-piece 1, or in the short cylinders or rings The spool however may be secured to the armature core if desired and ro- Said spool is wound with insulated wire 14, and as shown and operated is an induction coil. Its electricity is inducer that is, its wire is energized by the alternations in the polarity of the armatu re while the machine is in operation. The coil, as shown in the drawings is inductively and immediately excited by means of the magnetism induced in the middle portion of the core 7, across the spaces 8, by the endportions of said core on which the armaturemagnets or pole-pieces 11 are mounted.

On one end of the shaft (5, is mounted a pole-changer 15 which rotates with said shaft. Said pole-changer may be of any approved construction. It may also be fixed to revolve on a separate shaft, if desired. Two collectors or collecting rings 16,17 are secured to the shaft 6. These rings may be used or dispensed with, according to circumstances, as hereinafter explained.

The several modes in which the machine may be operated will now be described. The field and armature magnets and the spool 13 having been suitably wound with insulated wire, so that each pole piece in succession shall be of opposite polarity, as indicated by the letters N, S, Figs. 1 and 2, the connections of the wires are or may be thenmade as follows:-The end-magnets 11 of the armature are connected in circuit by their wires 12, passing, as shown in dotted lines, through the annular space between the armature core 7 and the shaft 6-the free end of one wire the free end of the other wire to the collect ing ring 17. Each of these rings is then connected by short wire connections 18, 19, and their branches to the bars of the pole-ch anger 15, as clearly seen in Fig. 1. The end field magnets are connected by their wires 4, whose free ends respectively connect with brushes a, b, which are set to have tangential contact with the bars of the rotary pole-changer 15, as clearly seen in Fig. 1. As also seen in Fig. 1, the induction-coil wound upon the spool 13, has the free ends or terminals of its wire 14 brought opposite each other, the interposed letters 00 indicating incandescent lamps which close the circuit between said terminals. In Fig. 4, a modification of this connection is shown. The ends of the wires 14, are connected to the brushes 0, d, which touch the collectors or collecting rings 20, 21 (shown in dotted linesin Fig. 1) connected by short wires 22, 23 and branches to the bars of the polechanger 15, as clearly shown in Fig. 4.

The operation of the machine as a dynamo, connected as shown in Fig. 1, is as follows: When the shaft 6 is rotated, by any external source of power, the alternating current produced by the armatures rotation is changed by the pole-changer and energizes the fieldmagnets with a continuous current. At the same time the armature inductively energizes, by its alternating magnetism, the inductioncoil 14, as hereinbefore described. This current so induced in said coil is well adapted for lighting purposes and may be so employed, as shown in Fig. 1, or said current may be used for other work. Part of the current generated may, at the same time, be taken off from the rings 16, 17, as an alternating current before reaching the pole-changer and 'used for lighting purposes or other work, as

may be desired. If said rings be not so used, the ind notion-coil will still discharge its said office, but, it may be advantageous and, under some circumstances, a more economical mode of operating the dynamo, to take the current in its two phases, from the machine both from the armature, direct, and from the induction-coil as above described.

The operation of themachine, asa dynamo, connected as shown in Fig. 4, is as follows: The alternating current induced in the induction coil 14, by the armatures rotation is used through the medium of the brushes 0, (l, collecting rings 20, 21, wires 22, 28 and branches, pole-changer 15, brushes a, I), and wires 4 to energize the field-magnets with a continuous current. The wires 4, however, when desired, may be connected to a storagebattery to charge the same,or to do ot her external work requiring a continuous current. In this case, the field could be excited as shown in Fig. 1, (where the coil 14 is in alamp circuit) as hereinbefore explained. The work of the induction-coil, however, if desired, might be divided between exciting the field and simultaneously doing some kind of being connected to the collecting ring 16 and 1 external work. But if the field be excited,

ITO

not by the armature as shown in Fig. 1, but by the induction coil 14, as shown in Fig. 4, (the wires 18, 19, Fi 1 being dispensed with) then an unchanged alternating current may still be taken off from the collecting rings 16, 17, (Fig. 1) in the same manner as before explained, and used for lighting purposes or other work suited to such current. It willbe observed that if the induction-coil 14 is secured to revolve with the armature as hereinbefore described, the brushes 0, d, and even the rings 16, 17, as mere means of connecting the pole changer with either the inductioncoil or armature, may be omitted.

This machine may be converted from a dynamo into a motor by supplying itwith either an alternating or a continuous current.

First, with an alternating current, the mannerof operation as shown in Fig. 1, is as follows:The collectors 16, 17, being put in circuit with the necessary current, part of said current will be converted into a continuous current in passing through the pole-changer 15 t0 the field-magnets 3; the remainder of the current unchanged will energize the armature magnets 11, the alternations in this current effecting the necessary change of polarity in said magnets to effect the rotation of the armature. Whatever amount of alternating current may be induced in the induction coil 14, by the armatures rotation, may be utilized as desired for any suitable work.

Second. If the current to be used be a continuous current, then it must be led by circuit to enter the pole changer 15, (Fig. 1) when one portion thereof will directly energize the field, and the other portion, changed by the pole-changer into an alternating current, will energize the armature, and perform its oflice, exactly as just described, where the alternating current directly entered the collectors 16, 17.

If connected as shown in Fig. 4, the machine is operated as a motor as follows:

First. With an alternating current, said current is led by circuit to enter the collectors 20, 21, whence part goes, through pole-changer 15, to energize the field as a continuous current. The remainder of the current, unchanged, passes through the coil 14 which then inductively energizes the armature with an alternating current and thereby effects the armatures rotation.

Second. If a continuous current be used it must be led by circuit through the brushes a, Z), (Fig. 4) into the pole-changer 15. One part of the current unchanged will thus energize the field through the wires 4, with a continuous current, and the remainder of the current changed in passing through the pole changer will traverse the coil 14, which will thus, as before explained, inductively energize the armature with an alternating current and thus effect the armatures rotation.

WVhen using the machine as a motor, if it be desired to energize the field by the inductioncoil 14, the wires 18, 19, may be dispensed withand an alternating current put, in circuit, into the collectors 16, 17, which current will directly energize the armature. The armature will then inductively excite the induction-coil14, which coil will in turn, through the pole-changer 15 and connections shown in Fig. 4, and as already described, energize the field-magnets with a continuous current.

If a continuous current only were obtainable to run the machine as a motor, it would be preferable to excite the field with said current in the manner hereinbefore described, instead of first causing this current to ind uctively excite the induction-coil 14, and then said coil to excite the field through a circuit therewith.

The pole-changer 15, is shown, for convenience, in Figs. 1 and 4 with its bars n projected upon a plane. The end-view in Fig. 2,

however, shows it cylindrical, or of a ringshape, adapted to rotate on the armature shaft. Each alternate bar a, is connected in circuit by wires to, in full lines, and t in dotted lines, thus forming two sets of bars, each set connected in separate series and each series alternately becoming plus and minus, or in other words, alternately changing the polarity of the current delivered. It will be observed therefore, that this pole-changer is not a commutator. A series of mere collectors, such as constitutes a commutator, acts to change an alternating into a continuous current by delivering each alternation of current, having the direction bearing the plus or positive name, to one brush and each alternation having the opposite or negative name to another brush, so that a new circuit having a continuous or non-alternating character is thus established.

The pole-changer 15, shown in the drawings, by reason of its construction, while changing the current from alternating to continuous and vice versa, as hereinbefore explained, is a much less complicated device than a commutator and by its introduction between the induction coil 14 and the field as seen in Fig. 4, avoidance of sparking is socured. For, in such case the coil may excite the field by a high voltage current through the pole-changer, while the current taken directly from the armature, for lighting or other external work, may be a large ampere-current.

I do not confine myself to the special arrangement of an induction coil 14, between the end-pole-pieces 3 and 11. For, it is obvious that said pole-pieces may be placed nearer together with an induction-coil on each outer side of them, or if but one set of said polepieces be used an induction coil may be placed on either side or both sides of them, without in any wise departing from my invention.

A compact self-contained machine (when used as a dynamo, either self excited or not) is thus provided whose relation of ampere to volt current can be nicely adjusted through ITO the intervention of the induction coil or coils, or considerably varied by the substitution of a coil or coils wound with more orless orheavier or lighter wire, without disturbing the windings of the armature or field magnets. \Vith but short connections between any of the parts for receiving or delivering currents, very ready divisions of the currents may also be effected. For instance (with but one simple pole changer) an alternating current may be taken direct from the armature, and one portion of this current utilized unrectified, and another portion, diverted through the polechanger, to excite the field'magnets, as a continuous current. A third current maybe taken, through the same pole changer from the induction coil or coils and used as acoutinuous current to charge a storage battery -or do other work requiring a continuous current. The compactness of this self-contained rotary converter-machine still provides for and permits the shaft or core of the armature (either inductively, or otherwise, excited by the armature proper) to be utilized to inductively excite the coil or coils, while leaving provision and ample room for each armature and field pole piece to carry its own winding. The construction likewise admits, mechanically, such proportions of parts and variations in relative windings of parts as to obtain high economic efficiency using the term efficiency in its strictly technical sense.

Some of the advantages of this machine operated as a dynamo may be summarized as follows:

The armature can be rotated in either direction by belt or otherwise from any source of power without change in adjustment of any parts of the machine. Power can thus be conveniently taken from a revolving car-axle to rotate the armature.

The machine, though generating an alternating current, excites its own field with a continuous current through the intervention of a simple non-sparking pole-changer. The machine, also, while operating at a moderate speed, can charge a storage-battery with a continuous current by day, so that the battery may charge the field at night, while the dynamo is running, and also keep the lights burning while the dynamo is at rest. The

machine can also be readily converted into an efficient motor, and if the induction-coil be used in such case, some of the machines assess power may be thereby conveniently distributed, in electrical instead of mechanical form, for lighting or other external work, or for the internal work of exciting either the field or the armature, as hereinbefore fully explained. I

Having thus fully described my said invention, I claim 1. A field-pole piece, for a dynamo electric machine, composed of soft iron and provided with hardened steel pins inserted in holes in said iron.

2. In an electric dynamo electric machine or motor, the combination of the following named elements within the machine, a series of radial field-magn ets, a rotary armature consisting of a core and a series of radial magnets, and an induction coil helically wound, at right angles to the armatures axis, and located at the side of the armature magnets.

3. In an electric dynamo electric machine or motor, the combination of the following named elements within the machine; endfield magnets; a rotary armature provided with end-magnets; and an induction coil located between the inner sides of said armature-magnets so as to be inductively excited by magnetism in said armatures core, substantially as and for the purposes set forth.

at. In an electric dynamo electric machine or motor, the combination of field magnets, an armature provided with radial magnets a pole changer, or commutating-device, and an induction coil or coils, surrounding the armature-core, in circuit with the pole changer and field magnets, so that while said coil or coils, are inductively excited by alternating currents, the field magnets receive a continuous current, through the pole-changer, from said coil or coils, substantially as and for the purposes set forth.

5. In an electric dynamo electric machine or motor, in combination with a field magnet or magnets, an armature provided with a core havinga part thereof separated from its poles by interposed non-magnetic material and inductively excited by the magnetism generated in said poles; and an induction coil or coils inductively excited by said part of said core, substantially as and for the purposes set forth.

CHARLES E. DRESSLER.

IVitnesses:

W. N. BENEDICT, FRANCIS P. REILLY. 

